This commit is contained in:
Patrick Decat 2014-10-15 14:51:44 +02:00
parent e98b3678df
commit 1f5c18720a
1 changed files with 17 additions and 14 deletions

View File

@ -1782,29 +1782,32 @@ CXWindowsScreen::doSelectEvents(Window w) const
// that we select PointerMotionMask on every window. we also select
// SubstructureNotifyMask in order to get CreateNotify events so we
// select events on new windows too.
//
// note that this can break certain clients due a design flaw of X.
// X will deliver a PointerMotion event to the deepest window in the
// hierarchy that contains the pointer and has PointerMotionMask
// selected by *any* client. if another client doesn't select
// motion events in a subwindow so the parent window will get them
// then by selecting for motion events on the subwindow we break
// that client because the parent will no longer get the events.
// FIXME -- should provide some workaround for event selection
// design flaw. perhaps only select for motion events on windows
// that already do or are top-level windows or don't propagate
// pointer events. or maybe an option to simply poll the mouse.
// we don't want to adjust our grab window
if (w == m_window) {
return;
}
// X11 has a design flaw. If *no* client selected PointerMotionMask for
// a window, motion events will be delivered to that window's parent.
// If *any* client, not necessarily the owner, selects PointerMotionMask
// on such a window, X will stop propagating motion events to its
// parent. This breaks applications that rely on event propagation
// behavior.
//
// Avoid selecting PointerMotionMask unless some other client selected
// it already.
long mask = SubstructureNotifyMask;
XWindowAttributes attr;
XGetWindowAttributes(m_display, w, &attr);
if ((attr.all_event_masks & PointerMotionMask) == PointerMotionMask) {
mask |= PointerMotionMask;
}
// select events of interest. do this before querying the tree so
// we'll get notifications of children created after the XQueryTree()
// so we won't miss them.
XSelectInput(m_display, w, PointerMotionMask | SubstructureNotifyMask);
XSelectInput(m_display, w, mask);
// recurse on child windows
Window rw, pw, *cw;